In a cellular system for a wireless communication, a cell which is a service area for transmitting a wireless signal of each base station tends to decrease in size, for various reasons, such as the increase of path loss caused by the usage of the high frequency and the provision of a MS-centric service. The small base stations for the small cell may be designed to be smaller in size and simpler in structure than a macro base station generally having a radius of 1 km.
A wireless communication system configured with a small cell may have a capacity of wireless resources that can be provided for a mobile station per area to be increased on average compared to a macro base station, but may have a density of cell borders higher than the macro cell. That is, if a service area of one macro base station is substituted with multiple small base stations, many cell borders may be generated among small base stations.
The increase of cell border areas in the small cells leads to an increase in the frequency of handovers. In general, since the data yield at a cell border is smaller than the yield at a position which is not a cell border, the fixed mobile station in a small base station may have higher data yield than the macro base station, but the mobile station moving in the small base station may undergo the decrease of the data yield at a cell border and handover at a higher frequency than the macro base station. In general, the process of a handover is known as a cause of increasing a probability of data transmission error and increasing overhead in a system.
Therefore, a technique for solving problems generated in a system configured with small base stations has been required.